ADM sanity check (VFR over the top)

[denverpilot]

Not my photo... and not lenticulars... but wicked cool.

 

[James331]

looks like there was plenty of clear between the puffs to me

 

[Tantalum]

the attitude indicator and directional gyro will start to wind down and eventually not be reliable

and the magnet ic compass, turn coordinator, and altimeter become your very best friends

Now if you lose electricity too... you're screwed. Keep the ball centered and heading straight??

 

[Harold Rutila]

@cowman, your thought processes sounded good to me. Had the clouds coverage become more dense, you could have also turned around back to scattered conditions if you had to.

 

[Clip4]

I disagree. During instrument training you typically don't practice partial panel work in conjunction with an engine failure, you practice it with the anticipation of having an instrument or vacuum pump problem. Having partial panel training will likely help in the case of an engine failure but I'd bet that the majority of pilots will have a significant performance degradation under those circumstances.

Keeping the wings level with the TC and trimming for best glide is really easy.

 

[azure]

I'd say marginal ADM. The concern is a bit different than has been pointed out, though.

Over the top above even modest mountains is quite different from overflying coastal stratus. As you found, mountain obscuration can be many thousands of feet thick, and VERY often requires flying near the service ceiling. You did not report density altitude. In summer, it can easily be 3000 higher than pressure altitude. But what you didn't see was that worsening weather doesn't just close holes. It can also, rather easily, go higher. Quickly. And you're already near your service ceiling.

As a rule, I don't overfly mountain obscuration. It's seldom worth it. There are exceptions if the crossing is very short and I can turn around easily (e.g. overflying one standing lenticular -- never fly under those).

Good points, but the OP was overflying the Appalachians not the Rockies or the Sierras, and out east here summer hasn't really kicked in yet. Density altitude and pressure altitude are pretty close - though that's likely to change in the next few days. I was a little concerned to read he went up to 12,500 without O2, but that's still well below from the service ceiling in most small piston planes (at least the BOOK service ceiling). Moreover, if you look at his photos, there wasn't really any mountain obscuration, just scattered cumulus with very little vertical development.

Now there are parts of the Appalachians where I'd be concerned about mountain turbulence, particularly in the NH White Mts. But that's far from where the OP was flying.

 

[MAKG1]

Good points, but the OP was overflying the Appalachians not the Rockies or the Sierras, and out east here summer hasn't really kicked in yet. Density altitude and pressure altitude are pretty close - though that's likely to change in the next few days. I was a little concerned to read he went up to 12,500 without O2, but that's still well below from the service ceiling in most small piston planes (at least the BOOK service ceiling). Moreover, if you look at his photos, there wasn't really any mountain obscuration, just scattered cumulus with very little vertical development.

Now there are parts of the Appalachians where I'd be concerned about mountain turbulence, particularly in the NH White Mts. But that's far from where the OP was flying.

The service ceiling for an Archer is around 13500. It doesn't take much for DA to push up there in the given conditions.

Mountain weather occurs in much smaller mountains than the Sierra. Sitting at KBUR, there was some pretty good obscuration over Mt Hollywood this morning, and little elsewhere. That's not even 2000 feet.

 

[Ghery]

I disagree. During instrument training you typically don't practice partial panel work in conjunction with an engine failure, you practice it with the anticipation of having an instrument or vacuum pump problem. Having partial panel training will likely help in the case of an engine failure but I'd bet that the majority of pilots will have a significant performance degradation under those circumstances.

I suspect that the majority of pilots will have a significant performance degradation with a simple vacuum pump problem. Unless you have an IPC and the CFII throws partial panel at you, when was the last time you flew with the AI and DG dead? For me it probably was my IR check ride, and that was a few years ago. I agree that when you add an engine failure on top of that performance is likely to suffer in a serious manner for most pilots.

 

[azure]

Yeah, no CFII has made me practice the way I had to do partial panel for my IR checkride, which was BOTH the HSI and AI covered, a very unrealistic failure. The AI alone is not a big deal as far as I'm concerned, in fact a vacuum pump failure would not be a serious issue other than legally as the ONLY instrument that it operates is the AI. HSI failure would be more serious, but I have a near-functional equivalent in the 480's nav page (except that it shows track rather than heading). The most serious single-point failure I could have (other than the engine) is one that no CFII has had me practice because it would be pretty hard to fly instruments that way, i.e. alternator failure. I would very quickly be left with ONLY the AI, and while I could control the plane that way to a degree, I would have no legal means of navigation and could only hold heading with the whisky compass. I guess I'd be falling back on the iPad and Foreflight if that happened for real.

 

[steingar]

My only concern is the 12.5k. FARs say you can only do that for a half our sans oxygen. Then again, I'll bet a bottle and cannula don't cost much from a medical supply company. But I myself have done this on a number of occasions. I just want to see that my destination is VFR and forecast to stay that way. Sometimes it's the only way to get past rocks. Beats the hell out of flying amoung them.

 

[Vance Breese]

It is my observation that it takes a pretty big “hole” to descend to land while maintaining the 2,000 feet horizontal clearance from clouds and the one mile visibility.

In my opinion 2,000 feet does not provide a lot of time to maneuver if an IFR pilot breaks out of the clouds while I am descending VFR through the “hole”.

 

[EppyGA]

My only concern is the 12.5k. FARs say you can only do that for a half our sans oxygen. Then again, I'll bet a bottle and cannula don't cost much from a medical supply company. But I myself have done this on a number of occasions. I just want to see that my destination is VFR and forecast to stay that way. Sometimes it's the only way to get past rocks. Beats the hell out of flying amoung them.

Above 12.5k, I'm sure he never hit 12,501

 

[Palmpilot]

My only concern is the 12.5k. FARs say you can only do that for a half our sans oxygen....

Actually, the half hour rule applies above 12,500, up to and including 14,000. It's interesting though that it says pressure altitude. I hadn't noticed that before.

91.211 Supplemental oxygen.
(a) General. No person may operate a civil aircraft of U.S. registry--

(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration;...​

 

[MAKG1]

Actually, the half hour rule applies above 12,500, up to and including 14,000. It's interesting though that it says pressure altitude. I hadn't noticed that before.

91.211 Supplemental oxygen.
(a) General. No person may operate a civil aircraft of U.S. registry--

(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration;...​

Pressure altitude is appropriate. The temperature in your lungs is always the same.

 

[TheGolfPilot]

I did a couple flights on days that looked like that back before I was a ifr guy. Always look in the distance for a way out. If the vfr minimums are "close" be aware of where the airways and approaches are. I reported a vfr guy floating down my Approach a year ago or so. No way the dude was maintaining cloud clearances and I was close enough to read his callsign. Do whatever you want just don't put my life at risk.

 

[midwestpa24]

There is one thing I would throw out there that I haven't seen mentioned yet. I too have flown "Over the Top", as well as hard IMC as an instrument rated pilot. And while you are legal on top of a low overcast, keep in the back of your mind what that means if the engine quits. Letting down through a layer is one thing, but what if the bases are 200 foot or lower. You won't have a lot of time or options available once or if you do break out. That is when I get the most concerned, flying single engine over areas that are low IFR.

 

[Palmpilot]

Pressure altitude is appropriate. The temperature in your lungs is always the same.

The thing that's interesting to me about it is that depending on whether the altimeter setting is above or below 29.92, it might or might not be legal to fly at 12,500 MSL without supplemental oxygen.

 

[steingar]

There is one thing I would throw out there that I haven't seen mentioned yet. I too have flown "Over the Top", as well as hard IMC as an instrument rated pilot. And while you are legal on top of a low overcast, keep in the back of your mind what that means if the engine quits. Letting down through a layer is one thing, but what if the bases are 200 foot or lower. You won't have a lot of time or options available once or if you do break out. That is when I get the most concerned, flying single engine over areas that are low IFR.

A good point, and I try and restrict these excursions to instances where there is flyable VFR Wx below. My thinking is in an emergency I'm pretty certain I can keep the shiny side up in a letdown, and once I'm in VFR conditions there really isn't any difference in loosing the mill above or below (except above you may have the ability to navigate toward a suitable landing site if you can keep a cool head).

 

[Todd82]

Good points, but the OP was overflying the Appalachians not the Rockies or the Sierras, and out east here summer hasn't really kicked in yet. Density altitude and pressure altitude are pretty close - though that's likely to change in the next few days. I was a little concerned to read he went up to 12,500 without O2, but that's still well below from the service ceiling in most small piston planes (at least the BOOK service ceiling). Moreover, if you look at his photos, there wasn't really any mountain obscuration, just scattered cumulus with very little vertical development.

Now there are parts of the Appalachians where I'd be concerned about mountain turbulence, particularly in the NH White Mts. But that's far from where the OP was flying.

I won't mention the airline even though they're long since gone, but I was in the back of a SF34 directly over HGR (probably at 11,000) on a severe clear cold winter morning when we hit evidently a mountain wave that sent the poor cute little FA flying (into my lap ) and she broke her foot in the process. So yes, the eastern mountains can cause some nasty wave effects at times.

I did a ton of training time at ABE years ago, some gnarly stuff in that valley between Blue and South Mountains too when the wind flows right. Left downwind to 23 at LBE even on the upwind side of the mountains gets a little funky too sometimes.